| Water hydraulic transmission technology is widely favored by the hydraulic industry at home and abroad due to its obvious advantages of safety,environmental protection,and low cost.Especially today,the natural environment is getting worse and worse,and it has become a hot topic of subject development.As an important control element in water hydraulic transmission technology,the performance of the water hydraulic proportional valve affects the control performance of the water hydraulic system directly.With the advent of the digital age,the hydraulic industry has also been hit by the digital wave.The high-speed on-off valve has become the cornerstone of digital hydraulic roads and is widely used as a pilot component of digital hydraulic components due to its advantages of simple structure,fast response speed,and direct acceptance of digital signals without D/A conversion.A water hydraulic proportional valve based on a high-speed on-off valve is developed in this paper.The main work is as follows:Based on the investigation of a large number of domestic and foreign research materials,according to the product needs,the rated flow rate of the water hydraulic proportional valve is determined to be 30 L/min and its rated pressure is determined to be 10 MPa.Based on the characteristics of high frequency and low flow rate of high speed on-off valve,a water hydraulic high speed on-off valve with its own main spool is designed.The plate valve structure is used in both the main stage and the pilot stage,which reduces the processing difficulty and improves the sealing reliability.Firstly,the parameter calculation and structural design of the valve body and the electromagnet are performed after the solutions to solve the technical difficulties of the water hydraulic high-speed on-off valve are proposed.The Maxwell electromagnetic simulation software is used to simu late the electromagnetic field distribution characteristics and output electromagnetic force.Based on the research of water hydraulic high-speed on-off valve,a water hydraulic proportional valve is developed.Four water hydraulic high-speed on-off valves are integrated into a full-bridge hydraulic resistance network.The three-position four-way proportional control performance is achieved by controlling the electrification sequence of the electromagnet.Based on the analysis of technical difficulties in i ntegrated design,the theoretical analysis of mechanical-hydraulic dynamics is performed.The water hydraulic proportional valve model is completed.Fluent flow field simulation software is used to analyze the flow field characteristics of the main valve port.It is found that the vortices in the flow channel lead to pressure loss and therefore causing the occurrence of cavitation.Re-optimizing the design of the main valve port runner basically eliminates this phenomenon.Finally,prototypes of water hydraulic high-speed on-off valves and water hydraulic proportional valves are manufactured and their dynamic and static characteristics are experimentally studied.The test results show that the pressure and flow control characteristics of the prototype are go od,and its dynamic and static characteristics basically meet the design requirements,which will generate good research value and application prospects. |
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